Subsequent studies, using conditional AR knockout mice lacking AR only in urothelial cells [31] or transgenic mice conditionally expressing AR in the bladder urothelium [32], further indicated the impact of AR within urothelial cells, but not other cells such as those in the liver or kidney that could considerably affect the metabolism of carcinogens, on the development of bladder cancer. Here, AR is linked to urinary bladder carcinoma.